U.S. patent application number 14/667847 was filed with the patent office on 2015-10-15 for cleaning industrial plant components to remove metal halides.
The applicant listed for this patent is WACKER CHEMIE AG. Invention is credited to Andreas BOCKHOLT, Klaus KAEPPLER, Christian KALTENMARKNER, Konrad MAUTNER, Javad MOHSSENI, Peter NUERNBERG.
Application Number | 20150291920 14/667847 |
Document ID | / |
Family ID | 53039688 |
Filed Date | 2015-10-15 |
United States Patent
Application |
20150291920 |
Kind Code |
A1 |
MOHSSENI; Javad ; et
al. |
October 15, 2015 |
CLEANING INDUSTRIAL PLANT COMPONENTS TO REMOVE METAL HALIDES
Abstract
Cleaning industrial plant components to remove silane, metal
halide, and organometallic halide contaminants and mixtures
thereof, involves treating the plant components with a liquid
nitrile or amine or mixture thereof or with a solution of a nitrile
or amine or mixture thereof in an aprotic solvent.
Inventors: |
MOHSSENI; Javad; (Leipzig,
DE) ; MAUTNER; Konrad; (Burghausen, DE) ;
NUERNBERG; Peter; (Nuenchritz/OT Leckwitz, DE) ;
KALTENMARKNER; Christian; (Burghausen, DE) ;
KAEPPLER; Klaus; (Burghausen, DE) ; BOCKHOLT;
Andreas; (Muenchen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WACKER CHEMIE AG |
Munich |
|
DE |
|
|
Family ID: |
53039688 |
Appl. No.: |
14/667847 |
Filed: |
March 25, 2015 |
Current U.S.
Class: |
134/22.14 ;
134/22.19; 134/42 |
Current CPC
Class: |
B08B 3/08 20130101; C11D
7/5009 20130101; B08B 9/027 20130101; C11D 7/32 20130101; C11D
11/0041 20130101; C11D 7/3209 20130101; C11D 7/5013 20130101 |
International
Class: |
C11D 7/50 20060101
C11D007/50; C11D 11/00 20060101 C11D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 9, 2014 |
DE |
10 2014 206 875.4 |
Claims
1. A method of cleaning industrial plant components to remove
silane, metal halide, and/or organometallic halide contaminants and
mixtures thereof, comprising treating the plant components with a
liquid nitrile, amine, or mixture thereof or with a solution of a
nitrile, amine or mixture thereof in an aprotic solvent.
2. The method of claim 1 wherein at least one metal halide or
organometallic halide is selected from the group consisting of
chlorides and organometallic chlorides of iron, cobalt, nickel,
chromium, titanium, copper, tin, zinc and aluminum.
3. The method of claim 1, wherein said method comprises employing
at least one nitrile of a mono- or polycarboxylic acid comprising
from 2 to 20 carbon atoms.
4. The method of claim 2, wherein said method comprises employing
at least one nitrile of a mono- or polycarboxylic acid comprising
from 2 to 20 carbon atoms.
5. The method of claim 1, wherein said method comprises employing a
solution of at least one liquid nitrile or amine or a mixture of at
least one nitrile and/or amine in an aprotic solvent selected from
the group consisting of ethers, chlorinated hydrocarbons,
hydrocarbons, siloxanes, ketones, esters, carbon disulphide,
nitrobenzene, and mixtures thereof.
6. The method of claim 2, wherein said method comprises employing a
solution of at least one liquid nitrile or amine or a mixture of at
least one nitrile and/or amine in an aprotic solvent selected from
the group consisting of ethers, chlorinated hydrocarbons,
hydrocarbons, siloxanes, ketones, esters, carbon disulphide,
nitrobenzene, and mixtures thereof.
7. The method of claim 3, wherein said method comprises employing a
solution of at least one liquid nitrile or amine or a mixture of at
least one nitrile and/or amine in an aprotic solvent selected from
the group consisting of ethers, chlorinated hydrocarbons,
hydrocarbons, siloxanes, ketones, esters, carbon disulphide,
nitrobenzene, and mixtures thereof.
8. The method of claim 4, wherein said method comprises employing a
solution of at least one liquid nitrile or amine or a mixture of at
least one nitrile and/or amine in an aprotic solvent selected from
the group consisting of ethers, chlorinated hydrocarbons,
hydrocarbons, siloxanes, ketones, esters, carbon disulphide,
nitrobenzene, and mixtures thereof.
9. The method of claim 1, wherein said method comprises cleaning
plant components in which silanes selected from chlorosilanes and
methylchlorosilanes are processed, said method comprising removing
AlCl.sub.3 and employing nitriles, and optionally also employing
aprotic solvents having a boiling point of at least 120.degree. C.
at 1013 hPa.
10. The method of claim 2, wherein said method comprises cleaning
plant components in which silanes selected from chlorosilanes and
methylchlorosilanes are processed, said method comprising removing
AlCl.sub.3 and employing nitriles, and optionally also employing
aprotic solvents having a boiling point of at least 120.degree. C.
at 1013 hPa.
11. The method of claim 3, wherein said method comprises cleaning
plant components in which silanes selected from chlorosilanes and
methylchlorosilanes are processed, said method comprising removing
AlCl.sub.3 and employing nitriles, and optionally aprotic solvents
having a boiling point of at least 120.degree. C. at 1013 hPa.
12. The method of claim 1, wherein adiponitrile is employed as a
liquid nitrile.
13. The method of claim 2, wherein adiponitrile is employed as a
liquid nitrile.
14. The method of claim 3, wherein adiponitrile is employed as a
liquid nitrile.
15. The method of claim 1, wherein adiponitrile is employed as a
liquid nitrile, in an aprotic solvent.
16. The method of claim 1, wherein the plant components are one or
more of pipes, stirred tanks, tubular reactors, distillation
columns and internals and packings thereof, thin film evaporators,
falling film evaporators, short path distillation apparatuses
including internals thereof, heat exchangers and vessels.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to German Patent
Application No. 10 2014 206 875.4 filed Apr. 9, 2014 which is
herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a method of cleaning industrial
plant components to remove silanes, metal halides and
organometallic halides, using a nitrile or amine.
[0004] 2. Background Art
[0005] Many crude industrial products and industrial product
mixtures, such as direct synthesis (Muller-Rochow synthesis)
mixtures, comprising chlorosilanes and methylchlorosilanes, or the
chlorosilane mixtures obtained from hydrochlorination of
metallurgical silicon, may comprise silanes, metal halides and
organometallic halides, particularly AlCl.sub.3. The silanes
present in the crude silanes are separated into pure silanes by
multi-stage distillation. The aforementioned impurities in the
crude silanes form deposits in the pipes causing problems which may
even culminate in blockage of the lines. The lines thus require
dismantling and cleaning, e.g. with water, at regular intervals.
This method of cleaning has two disadvantages. The first is cost
and inconvenience. Disassembly, cleaning and reassembly of lines is
costly and very time consuming. The second disadvantage of cleaning
with water is the formation, by hydrolysis of chlorosilane
residues, metal chlorides, and/or organometallic halides and/or
mixtures of metal halides/organometallic halides, of hydrochloric
acid which attacks the pipes. Acetonitrile is described as a
solvent for aluminum chloride [Zeitschrift fur anorganische und
allgemeine Chemie. Weinheim: Wiley-VCH, ISSN 0372-7874 Vol. 511 (4.
1984), p. 148].
SUMMARY OF THE INVENTION
[0006] The invention provides a method of cleaning industrial plant
components to remove contaminants selected from silanes, metal
halides, organometallic halides and mixtures thereof wherein said
method comprises treating the plant components with a liquid
nitrile or amine or mixtures thereof or with a solution of a
nitrile or amine or mixtures thereof in an aprotic solvent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0007] Contaminants, particularly metal halides, form deposits in
plant components. The contaminants are easily dissolved out from
the industrial plant components with nitriles or amines. The
deposits in the lines are incipiently or fully dissolved and
sluiced out. After cleaning, the plant components are dried and
brought back on stream. The cleaning residues may simply be sluiced
out and properly disposed of, for example by incineration.
[0008] Cleaning plant components with nitriles or amines obviates
the need for costly and time-consuming disassembly and cleaning
with water. The useful life of the plant components is extended
since the lines no longer come into contact with acidic water.
[0009] The contaminants are in particular metal halides and
organometallic halides which form acids on hydrolysis with water,
particularly organometallic chlorides. Examples include chlorides
and organometallic chlorides of iron, such as FeCl.sub.2,
FeCl.sub.3, cobalt, nickel, chromium, titanium, copper, tin, zinc
and preferably AlR.sub.xCl.sub.3-x, where R is an organo or
organosilane function, particularly methyl, and x is 0, 1, or 2,
particularly AlCl.sub.3.
[0010] Preferably employed nitriles are nitriles of mono- or
polycarboxylic acids preferably comprising from 2 to 20 carbon
atoms, more particularly from 5 to 12 carbon atoms. Preference is
given to nitriles of aliphatic saturated monocarboxylic acids, such
as acetic, propionic, butyric, valeric and caproic acids and of
fatty acids comprising up to 18 carbon atoms. Preference is also
given to dinitriles of aliphatic saturated dicarboxylic acids, such
as malonic, succinic, glutaric, adipic, pimelic and suberic acids.
Preference is given to nitriles having a boiling point of at least
120.degree. C. at 1013 hPa, more particularly at least 150.degree.
C. at 1013 hPa.
[0011] Particular preference is given to adiponitrile which has a
boiling point of 295.degree. C. at 1013 hPa and displays a strong
complexing affinity for metal ions due to its two nitrile groups.
Adiponitrile is an important intermediate in polyamide production
and is thus widely available and inexpensive.
[0012] The amines are preferably selected from primary, secondary
and tertiary aliphatic and aromatic amines. Polyamines comprising
not only primary and secondary but also tertiary amine functions
may be employed as well as monoamines.
[0013] Preferred monoamines conform to general formula (I)
NR.sup.1R.sup.2R.sup.3 (I),
where [0014] R.sup.1, R.sup.2, R.sup.3 are H or a monovalent
C.sub.1-C.sub.30 hydrocarbon radical optionally substituted by
substituents selected from F--, Cl--, OH-- and OR.sup.4 where
nonadjacent --CH.sub.2-- units of the R.sup.1, R.sup.2, and R.sup.3
radicals are optionally substituted by units selected from
--C(.dbd.O)-- and --O--, and [0015] R.sup.4 is a C.sub.1-C.sub.10
alkyl radical.
[0016] The monovalent hydrocarbon radicals R.sup.1, R.sup.2,
R.sup.3 may be linear, cyclic, branched, aromatic, saturated or
unsaturated. The hydrocarbon radicals R.sup.1, R.sup.2, R.sup.3
preferably comprise from 1 to 20 carbon atoms, particular
preference being given to alkyl radicals comprising from 1 to 6
carbon atoms, alkylaryl radicals, arylalkyl radicals each and
phenyl radicals.
[0017] Preferred polyamines conform to general formula (II)
R.sup.5.sub.2N--(CR.sup.6.sub.2).sub.a--(NR.sup.7--(CR.sup.6.sub.2).sub.-
b).sub.c--NR.sup.5.sub.2 (II),
where [0018] R.sup.5, R.sup.6, R.sup.7 are H or C.sub.1-C.sub.18
hydrocarbon radicals optionally substituted by substituents
selected from F--, Cl-- and OH-- where nonadjacent --CH.sub.2--
units of the R.sup.5, R.sup.6, and R.sup.7 radicals are optionally
substituted by units selected from --C(.dbd.O)-- and --O--, [0019]
a, b are integers of from 1 to 6, and [0020] c is 0 or an integer
of from 1 to 40. [0021] a, b are preferably 2 or 3. [0022] c is
preferably an integer of from 1 to 6. Preferably, a and b are
identical.
[0023] Examples of particularly preferred polyamines (A) of general
formula (II) include: [0024] diethylenetriamine
(H.sub.2N--CH.sub.2CH.sub.2--NH--CH.sub.2CH.sub.2--NH.sub.2),
[0025] triethylenetetramine
(H.sub.2N--CH.sub.2CH.sub.2--(NH--CH.sub.2CH.sub.2--).sub.2--NH.sub.2),
[0026] tetraethylenepentamine
(H.sub.2N--CH.sub.2CH.sub.2--(NH--CH.sub.2CH.sub.2--).sub.3--NH.sub.2),
[0027] pentaethylenehexamine
(H.sub.2N--CH.sub.2CH.sub.2--(NH--CH.sub.2CH.sub.2--).sub.4--NH.sub.2),
[0028] hexaethyleneheptamine
(H.sub.2N--CH.sub.2CH.sub.2--(NH--CH.sub.2CH.sub.2--).sub.5--NH.sub.2),
and mixtures of the abovementioned amines, such as are commercially
available as industrial products, for example AMIX1000.RTM. (BASF
SE).
[0029] Examples of further preferred monoamines and polyamines
include octylamine, nonylamine, decylamine, undecylamine,
dodecylamine (laurylamine), tridecylamine, tridecylamine (isomer
mixture), tetradecylamine (myristylamine), pentadecylamine,
hexadecylamine (cetylamine), heptadecylamine, octadecylamine
(stearylamine), 4-hexylaniline, 4-heptylaniline, 4-octylaniline,
2,6-diisopropylaniline, 4-ethoxyaniline, N-methylaniline,
N-ethylaniline, N-propylaniline, N-butylaniline, N-pentylaniline,
N-hexylaniline, N-octylaniline, N-cyclohexylaniline,
dicyclohexylamine, p-toluidine, indoline, 2-phenylethylamine,
1-phenylethylamine, N-methyldecylamine, benzylamine,
N,N-dimethylbenzylamine, 1-methylimidazole, 2-ethylhexylamine,
dibutylamine, dihexylamine, di-(2-ethylhexylamine),
3,3'-dimethyl-4,4'-diaminodicyclohexylmethane,
4,4'-diaminodicyclohexylmethane, ditridecylamine (isomer mixture),
isophoronediamine, N,N,N',N'-tetramethyl-1,6-hexanediamine,
N,N-dimethylcyclohexylamine, octamethylenediamine, 2,6-xylidine,
4,7,10-trioxatridecane-1,13-diamine,
4,9-dioxadodecane-1,12-diamine, di-(2-methoxyethyl)amine,
bis(2-dimethylaminoethyl) ether, Polyetheramin D230.RTM. (BASF SE),
2-(diisopropylamino)ethylamine, pentamethyldiethylenetriamine,
N-(3-aminopropyl)imidazole, 1,2-dimethylimidazole,
2,2'-dimorpholino diethyl ether, dimethylaminoethoxyethanol,
bis(2-dimethylaminoethyl) ether, Lupragen.RTM.N600--S-triazine
(BASF AG), 1,8-diazabicyclo-5,4,0-undec-7-ene (DBU),
3-(2-aminoethylamino)propylamine, 3-(cyclohexylamino)propylamine,
dipropylenetriamine, N4-Amin
(N,N'-bis(3-aminopropyl)ethylenediamine), AMIX M (BASF AG)
(=high-boiling morpholine derivatives),
1-(2-hydroxyethyl)piperazine, 2-(2-aminoethoxy)ethanol,
3-amino-1-propanol, 3-dimethylaminopropan-1-ol,
4-(2-hydroxyethyl)morpholine, butyldiethanolamine,
N-butylethanolamine, N,N-dibutylethanolamine,
N,N-diethylethanolamine, dimethylaminoethoxyethanol
(Lupragen.RTM.N107, BASF AG), methyldiethanolamine, diethanolamine,
triethanolamine, diisopropanolamine, triisopropanolamine,
1-vinylimidazole, 1-hexylimidazole, 1-octylimidazole,
1-(2-ethylhexyl)imidazole, and triisooctylamine.
[0030] Preference is given to amines having a boiling point of at
least 120.degree. C. at 1013 hPa, more particularly at least
150.degree. C. at 1013 hPa.
[0031] When solutions of nitriles or amines or mixtures of nitriles
and amines in aprotic solvents are employed, preference is given to
using solvents or solvent mixtures having a boiling point or
boiling range of up to 120.degree. C. at 1013 hPa. Examples of such
solvents include ethers, such as dioxane, tetrahydrofuran, diethyl
ether, diisopropyl ether, diethylene glycol dimethyl ether;
chlorinated hydrocarbons such as dichloromethane, trichloromethane,
tetrachloromethane, 1,2-dichloroethane, trichloroethylene;
hydrocarbons, such as pentane, n-hexane, hexane isomer mixtures,
heptane, octane, solvent naphtha, petroleum ether, benzene,
toluene, xylenes; siloxanes, in particular linear
dimethylpolysiloxanes comprising trimethylsilyl end groups
preferably comprising from 0 to 6 dimethylsiloxane units, or cyclic
dimethylpolysiloxanes preferably comprising from 4 to 7
dimethylsiloxane units, for example hexamethyldisiloxane,
octamethyltrisiloxane, octamethylcyclotetrasiloxane and
decamethylcyclopentasiloxane; ketones, such as acetone, methyl
ethyl ketone, diisopropyl ketone, methyl isobutyl ketone (MIBK);
esters, such as ethyl acetate, butyl acetate, propyl propionate,
ethyl butyrate, ethyl isobutyrate; carbon disulfide and
nitrobenzene, or mixtures thereof.
[0032] The concentration of the nitriles and/or amines in the
aprotic solvents is preferably at least 1 g/l, more preferably at
least 5 g/l, and most preferably at least 10 g/l.
[0033] The method is preferably carried out at a temperature of
from 0.degree. C. to 100.degree. C., more preferably from
15.degree. C. to 30.degree. C., and at a pressure of from 500 hPa
to 2000 hPa, more preferably from 900 hPa to 1200 hPa.
[0034] One particular embodiment comprises cleaning plant
components in which silanes selected from chlorosilanes and
methylchlorosilanes are processed. AlR.sub.xCl.sub.3-x, in
particular AlCl.sub.3, is removed from these plant components with
high-boiling organochlorosilanes. Acetonitrile is less suitable for
these plant components since acetonitrile has a boiling point of
82.degree. C. at 1013 hPa and thus also has an appreciable vapor
pressure at room temperature. Its high vapor pressure hampers the
use of acetonitrile in pipe cleaning since acetonitrile is
flammable. In addition, acetonitrile must not become entrained in
silane mixtures of the distillation since its boiling point is very
close to that of chlorosilanes and methylchlorosilanes and the
acetonitrile would then itself become an impurity. These plant
components are cleaned using nitriles alone or in combination with
aprotic solvents having a boiling point of at least 120.degree. C.
at 1013 hPa. Particular preference is given to adiponitrile.
[0035] Examples of plant components include pipes, stirred tanks,
tubular reactors, distillation columns and internals and packings
thereof, thin film evaporators, falling film evaporators, short
path distillation apparatuses including internals thereof, for
example wipers in thin film evaporators, but also heat exchangers
and vessels, such as tanks and flasks.
[0036] While embodiments of the invention have been illustrated and
described, it is not intended that these embodiments illustrate and
describe all possible forms of the invention. Rather, the words
used in the specification are words of description rather than
limitation, and it is understood that various changes may be made
without departing from the spirit and scope of the invention.
* * * * *